Abstract Background/Introduction Task force statements advocate digital health interventions to promote self-care behaviour and health-related quality of life (HRQL) in patients with chronic heart failure (CHF). There is a need to identify therapeutic components of digital interventions to improve the efficacy and replicability of these CHF interventions. Purpose The Canadian e-Platform to PrOmote BehavioRal Self-ManagemenT in Chronic Heart Failure trial (CHF-CePPORT) evaluated the efficacy of automated digital counseling to improve HRQL at 12 months, using the Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS). Our aim was to identify therapeutic components of the CHF-CePPORT protocol that were independently associated with KCCQ-OS endpoint. Methods CHF-CePPORT was a multicenter, randomized controlled trial with a 2-parallel group, double blind design, and assessments at baseline, 4- and 12-months. This substudy focused on patients randomized to the automated digital counseling arm of CHF-CePPORT. Ordinal logistic regression was used to identify components of the protocol that predicted higher KCCQ-OS tertile at 12-months, according to schedule of automated digital contact, modality of content, and clinical content theme – see Figure. Results From the sample enrolled in CHF-CePPORT (n=230), 117 patients were included in this substudy: female, n=24 (20.5%), median age=60 years (IQR, 52, 69), New York Heart Association Class 1, n=45 (38.5%), Class 2, n=48 (41.0%), and Class 3, n=16 (13.7%). Baseline KCCQ-OS was median=82.3 (IQR, 67, 93). Patient engagement with the digital counseling platform over 12 months was as follows: Median (IQR) total logons = 79 (24, 133), Total logon time = 5.8 hours (1.6, 9.8). Total logon time during the initial phase of the trial (sessions 1–16), with weekly scheduled sessions was independently associated with a higher 12-month KCCQ-OS tertile score (p=0.003). Subsequent sections (sessions 17–24, and 25–28) were not independently associated with the 12-month KCCQ-OS (p=0.56 and p=0.91 respectively). Within sessions 1–16, the 12-month KCCQ-OS was associated with the use of counseling and dramatic videos (p=0.04) and e-tools/trackers (p=0.007), but not conventional information/education pages (p=0.80). Content themes associated with the 12-month KCCQ-OS included motivational counseling (sessions 5–8) with self-assessment tools and trackers (p=0.04). Cognitive behavioural guidelines for HF self-care were also associated with 12-month KCCQ-OS tertiles when presented by expert and dramatic videos (p=0.02) as well as self-assessment etools/etrackers (p=0.02). Self-assessment tools and trackers for HRQL (sessions 15–16) were also associated with higher KCCQ tertiles at 12 months (p=0.01) – see Table. Conclusion(s) The results of this study confirm the importance of using key components from evidence-based, clinically organized protocols of behavioural counseling to promote HRQL for patients with CHF. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research